KABUL, Afghanistan - Roadside bombs killed five NATO service members in southern Afghanistan on Friday, the alliance said.
The deaths bring to nine the number of coalition troops killed since the start of the year.
At least 544 NATO troops died in Afghanistan in 2011. It was the second deadliest year for the coalition in the 10-year war.
Four troops died in one of Friday's bombings and one was killed in a separate blast. The alliance said both incidents occurred in southern Afghanistan but provided no further details.
U.S. and NATO forces in Afghanistan have surged since 2009 and the government's army and police have rapidly expanded, resulting in the capture and killing of thousands of insurgents. Nonetheless, the guerrillas have retained their capability to inflict losses on coalition forces.
Faced with overwhelming allied superiority in numbers and firepower, the Taliban largely avoid direct combat, relying instead on roadside bombs, small ambushes and hit-and-run tactics to harass NATO and government forces.
Taliban military activities typically abate during the winter months, due to heavy snows and bitter cold in the rough mountain terrain.